redmine_workload/lib/dateTools.rb:25: syntax error, unexpected ':', expecting ')'

[scripthead]

On Redmine 2.3.0.stable.11744 I get this:

www-data@redmine-workload:/storage/redmine$ rake redmine:plugins:migrate RAILS_ENV=production
rake aborted!
/storage/redmine/plugins/redmine_workload/lib/dateTools.rb:25: syntax error, unexpected ':', expecting ')'
...ser}/#{timeSpan}", expires_in: 12.hours) do
                              ^
/storage/redmine/plugins/redmine_workload/lib/dateTools.rb:25: syntax error, unexpected ')', expecting kEND
...eSpan}", expires_in: 12.hours) do
                              ^